Cloud Based 5G Wireless Networks pdf pdf
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Stan Zdonik, Shashi Shekhar, Jonathan Katz, Xindong Wu, Lakhmi C. Jain, David Padua, Xuemin (Sherman) Shen, Borko Furht, V. S. Subrahmanian, Martial Hebert, Katsushi Ikeuchi, Bruno Siciliano, Sushil Jajodia and Newton Lee More information about this series at
Yin Zhang and Min Chen
Cloud Based 5G Wireless Networks
Yin Zhang School of Information and Safety Engineering, Zhongnan University of Economics and Law, Wuhan, Hubei, China Min Chen School of Computer Science and Technology, Huazhong University of Science and Technology, Wuhan City, China
ISSN 2191-5768 e-ISSN 2191-5776
ISBN 978-3-319-47342-0 e-ISBN 978-3-319-47343-7 DOI 10.1007/978-3-319-47343-7 Library of Congress Control Number: 2016954921 © The Author(s) 2016 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed.
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Preface
In recent years, information communication and computation technologies are deeply converging, and various wireless access technologies have been successful in deployment. It can be predicted that the upcoming fifth-generation mobile communication technology (5G) can no longer be defined by a single business model or a typical technical characteristic. 5G is a multi-service and multi-technology integrated network, meeting the future needs of a wide range of big data and the rapid development of numerous businesses, and enhancing the user experience by providing smart and customized services. In this book, we introduce the general background of 5G wireless networks and review related technologies, such as cloud-based networking, cloud platform for networking, definable networking, green wireless networks, which are capable of providing a virtualized, reconfigurable, smart wireless network.
We are grateful to Dr. Xuemin (Sherman) Shen, the SpringerBriefs Series Editor on Wireless Communications. This book would not be possible without his kind support during the process. Thanks also to the Springer Editors and Staff, all of whom did their usual excellent job in getting this monograph published.
This work was supported by China National Natural Science Foundation (No. 61572220).
Yin Zhang Min Chen Wuhan, China September 2016
Acronyms
3GPP 3rd Generation Partnership Project
4G
The fourth generation mobile cellular communication system
5G The fifth-generation mobile communication AMQP Advanced Message Queue Protocol Amazon EC2 Amazon Elastic Compute Cloud API
Application Programming Interface
ARFCN Absolute Radio Frequency Channel Number AVI Architecture of the virtualization infrastructure BBU Bandwidth Based Unit BGP-LS
Border Gateway Protocol Link-State
BSC Base Station Controller BSS Business Support Systems CC Cloud Controller CDMA
Code division multiple access
CDN Content delivery network CDPI Control-data-plane interface Cloud-RAN Cloud Radio Access Networks COTS
Commercial off-the-shelf
D2D Device-to-device DC Data center DG CONNECT Directorate General for Communications Networks, Content& Technology DHCP
Dynamic Host Configuration Protocol
EMS Element management system eNobeB Evolved Node B EPC Evolved Packet Core ETSI
European Telecommunication Standards Institute
EVE Evolution and Ecosystem EXR Exclusive routing FDMA Frequency division multiple access FIS
Flow instruction set
FMC Fixed mobile convergence ForCES Forwarding and Control Element Separation FRP Functional reactive programming GGSN
GPU Graphics Processing Unit HFT Hierarchical Flow Tables HSPA+
Evolved High Speed Packet Access
IAAS Infrastructure as a service
ICT Information and Communication Technology
IETF Internet Engineering Task Force
IFA
Interfaces and Architecture
IGP Interior Gateway Protocol
IMT-A International Mobile Telecommunication-Advanced IoT Internet of Things IoV
Internet of Vehicles
IP Internet Protocol
IRTF Internet Research Task Force
ISG Industry Specification Group
IT
Information technology
ITU International Telecommunications Union
ITU-T
ITU Telecommunication Standardization Sector
KVM Kernel-Based Virtual Machine LGW
Local Gateway
LTE Long term evolution MAC Media Access Control MANO Management & orchestration MBMS
Multimedia Broadcast Multicast Services
MCDN Mobile Content Distribution Network MCN Multi-hop Cellular Networks MCN Mobile cloud networking METIS
Mobile and wireless communications Enablers for theTwenty-twenty Information Society
MIMO Multiple-input multiple-output MMC Massive machine communication MME Mobility Management Entity MN
Moving network
MOCN Multi-operator Core Network NaaS Networking as a Service NBI Northbound interface NE
Network element
NFV Network Foundation Virtualization NFVI NFV infrastructure NFVO
NFV Orchestrator
NIB Network information base NMS Network management system NP Network processor NUAGE
Nuage Virtualized Services Platform
OFDM Orthogonal frequency division multiplexing ONF Open Networking Foundation ONOS Open Network Operating System OSGi
Open Services Gateway initiative
OSS Operation support system P&P Performance & Portability P2V Physical-to-Virtual PBX
Private branch exchange
PGW Packet Data Network Gateway POC Proof of concept QoE Quality of Experience QoS
Quality of Service
R&A Reliability & Availability RAN Radio access networks RANaaS RAN-as-a-Service REL
Reliability
REST Representational State Transfer RNC Radio Network Controller RRU Remote Radio Unit RSSI
Received signal strength indicator
SA Software architecture SAL Service abstraction layer SCN Single-hop Cellular Networks SDN
Software defined network
SDNGR Software-Defined Networking Research Group
SEC Security SGSN Serving GPRS Support Node SGWServing Gateway
SNA Shared Network Area SO Service Orchestrator SON
Self-Organization Network
T-NOVA Network function as-a-service over virtualized infrastructures
TDMA Time division multiple access TMSI Temporary Mobile Subscriber Identifier TSCTechnical Steering Committee
TST Testing, Experimentation and Open Source UDN Ultra dense networking URC Ultra reliable communication
V2V
Virtual-to-Virtual
V2P Virtual-to-Physical vCDN virtual Content Distribution Network vCPE virtual Customer Premise Equipment vEPC
virtualized Evolved Packet Core
vIMS virtual IP Multimedia Subsystem
VLAN Virtual local area network
VM Virtual machine
VMM
Virtual Machine Monitor
VNF Virtual Network Function
VNF-FG
VNF Forwarding Graph
VNFC
VNF Component
VNFL
VNF Link
VNS Virtualized network services
VPN Virtual private network
VXLAN Virtual Extensible LAN WG
Working group
WLAN Wireless local area network WRC World Radio Communication Conference
Contents
© The Author(s) 2016
Yin Zhang and Min Chen, Cloud Based 5G Wireless Networks, SpringerBriefs in Computer Science, DOI 10.1007/978-3-319-47343-7_1
1. Introduction 1 2 Yin Zhang and Min Chen
(1) School of Information and Safety Engineering, Zhongnan University of Economics and Law, Wuhan, Hubei, China
(2) School of Computer Science and Technology, Huazhong University of Science and Technology, Wuhan City, China
Abstract
In recent years, information communication and computation technologies are deeply converging, and various wireless access technologies have been successful in deployment. It can be predicted that the upcoming fifth-generation mobile communication technology (5G) can no longer be defined by a single business model or a representative technical characteristic. 5G is a multi-service and multi- technology integrated network, meeting the future needs of a wide range of big data and the rapid development of numerous businesses, and enhancing the user experience by providing intelligent and personalized services.
1.1 The Development of Wireless Networks
Wireless networks have been rapidly developing in the recent 20 years. They have brought a huge impact to all aspects of people’s lifestyles in terms of work, social, and economy. Human society has entered the information era with the support of big data. The demand for advanced technologies to support future applications and services in all aspects of people’s living is continuously increasing. Moreover, with the rapid development of wearable devices, Internet of Things (IoT), Internet of Vehicles (IoV), etc., both numbers and types of smart devices accessing to wireless networks will overwhelm the ability of existing networks.
According to “Global Mobile Data Traffic Forecast Update 2014–2019 White Paper” by Cisc
, the global mobile data traffic at the end of 2013 reached 1.5 exabytes, increased by 81 %
from 2012, while the mobile data traffic of 2014 was nearly as 18 times as the total annual amount of Internet data in 2000. Moreover, the global mobile data traffic from 2014 to 2020 is continuing to grow exponentially, and it estimates that the demand for data capacity will grow 1000-fold in the next 10 years. Especially, the mobile data generated by cellular networks will account for more than 60 %, and the mobile wireless networks traffic in 2020 will be as 500 times as 2010 [
]. The explosion
of mobile data is bringing the following challenges for the wireless networks:
Connectivity capacity: Traditional communication technologies mainly provide human-to-
human communication. With the rise of IoT and other related technologies, more devices can communication should be satisfied. Thus, the fifth-generation mobile communication technology (5G) is expected to provide a ubiquitous solution to connect everything any time, any where.
Network performance: Due to more novel applications accessing to the mobile networks,
people expect to easily and rapidly access to a rich variety of information. In any environment, users can conveniently be provided real-time access to multimedia resources, and other useful information through 5G networks.
Resource optimization: The Quality of Service (QoS) of traditional communication
technologies is often improved by upgrading the hardware and other infrastructures. However, this approach needs more cost and easily cases a waste of resources. 5G networks are expected to intelligently identify the communication scenarios, dynamically allocate network resources and provide considerable connectivity and network performance on demand, and improve the efficiency of existing resources. Surge in broadband mobile data services demands for high-throughput, low-latency data transmission, so promoting communication operators laid more and more intensive base station equipment to meet the coverage capacity of user groups in different regions and hotspots, while the traditional cellular network architecture in the long-term evolution is also becoming heterogeneous, complex, and intensive. In November 2010, the International Telecommunication Union (ITU) approved the International Mobile Telecommunication-Advanced (IMT-A) international standard. Since then, the fourth generation mobile cellular communication system (4G) based on this standard is widely implemented all over the world, and the 4G Long-Term Evolution (LTE) network is one of the most representative technique
. However, people are continuing to expect more advanced
communications, so the innovation of mobile network technology will never stop. So far, though 4G has been matured, with the publishing of IMT-2020 international standard, 5G is improving rapidly. Compared to 4G-LTE, 5G is expected to support 10 times the present data capacity, 10–100 times the present number and speed of available connection, 10 times the present battery life time and one-fifth the present delay. In 2015, the 3rd Generation Partnership Project (3GPP) published the main technical requirements for performance comparison between IMT-A and IMT-2020, from which it is
,
1.2 5G Wireless Networks
5G is gradually becoming the new hotspot of academia and industry [
]. It is expected that 5G will be
the leading mobile communication technology after 2020 to meet the information requirement of the human society by interconnecting the wireless world without barriers
]. With the enhancement of
bandwidth and capacity of wireless mobile communication systems and the rapid development of the applications of mobile networks, the IoT and mobile wireless networks for personal usage and business will be evolved with fundamental ecological changes. Wireless communication, computer, and information technology will be closely and deeply interworked, and the novel hardware and software will be rapidly improved to support the development of 5G industry.
Although 5G has been proposed with a basic idea and prototype, it meets a series of key technical challenges and tremendous obstacles. In particular, there is a profound contradiction between the growing demand for wireless communication services and the increasingly complex heterogeneous network environment, which causes greater resource and energy consumption for improving network capacity. Since the twentieth century, with the increasingly prominent global warming, climate anomalies, energy crisis, and other related issues, the development of low-carbon economy has become the consensus of the human community, and it is a fundamental requirement to develop a sustainable, resource-optimized and energy efficient green communications technology, and network infrastructure. As shown in Fig.
, it effectively reduces the resources and energy consumption, and
improves resource and energy efficiency in accordance with the principles and re-examine the design of future wireless communication networks. Therefore, 5G is a significant research and innovation, and the development of 5G technology is the only way for wireless networks evolution.
Fig. 1.1 Sustainable Green Communications Evolution for 5G by 2020 (Source: UEB—Labex COMIN Labs, 2014)
In particular, Shannon channel capacity theory suggests that there is a linear relationship between the capacity and bandwidth, while the relationship between the capacity and the power is logarithmic. The fundamental theorem reveals the existence of a compromise between the required power and spectral bandwidth, which means that it is available to decrease the energy consumption by increasing the effective bandwidth within a limited capacity, and vice versa. It has been proved that if mobile operators can use the novel wireless access technology to dynamically manage their licensed spectrum and make full use of the available spectrum resources to improve the utilization and the energy efficiency, the system can save about 50 % energy consumption. In addition, several statistics also show that the substantial increase in energy consumption, as well as spectrum resource, is another bottleneck for the future as the main heterogeneous wireless communication network development. Specifically, if the existing solutions are desperate used to improve the system capacity, coverage, spectral efficiency, and other properties, it will significantly increase the network energy consumption, even delay or hinder the sustainable development of future heterogeneous wireless communication network.
Furthermore, with the improvement of the bandwidth and capacity for wireless networks, the mobile applications for individuals and industries are rapidly developed, and the mobile communication related industrial ecology will gradually evolved. 5G is no longer just a air interface technology with higher rate, greater bandwidth, greater capacity, but also a intelligent network for business applications and user experience. Specifically, 5G should achieve the following objectives:
Sufficiency: The user’s reliance on mobile applications require the next-generation wireless
mobile networks to provide users with enough speed and capacity. Predictably, major mobile transmission, some special scenarios demand for more than 100 Mbps to support ultra high- definition video transmission, and even some particular devices demand for more than 10 Gbps to support the holographic business. With sufficient speed and capacity, the wireless network traffic is expected to be increased. Because the daily traffic from each user is expected to reach more than 1 GBytes, while the special terminals with high traffic volume demand for even more than 10 GBytes.
Friendliness: Ubiquitous coverage and stable quality are the basic requirements for the
communication systems. The existing mobile communication systems almost cover essentially the entire population, but there are many coverage hole, such as wilderness, ocean, Antarctica, and aircraft. Moreover, the mobile communication systems may be unavailable in some cases, such as on the high-speed rail and in the tunnels. Future mobile communication systems must include a various communication techniques to provide the users with ubiquitous coverage and reliable communication quality. 5G wireless networks are expected to provide always-online user experience that the delay of service connection and information transmission is imperceptible. Functionally, in addition to the basic communication capabilities and various multimedia applications, more comprehensive applications are provided convenience and efficiency of working and life.
Accessibility: Although 5G includes various complex techniques, from the user’s point of view,
it is a simple and convenient approach including the following advantages: (1) access technology is transparent to the users, while the network and devices switching are seamless and smooth; (2) the connection between multiple wireless devices is convenient and compatible; (3) the mobile terminals are portable, especially the wearable devices; and (4) the interface to various applications and services are unified.
Economy: This is mainly reflected in two aspects: (1) Although the network traffic continues to
increase, the tariff per bit is greatly reduced and it will be even lower. (2) The investment in infrastructure is reduced, while the network resource utilization is improved through dynamic allocation in order to improving the QoS.
Personality: Future communication is a people-oriented, user-experience-centric system that the service is available to be customized by users according to their individual preferences.
Specifically, according to the user’s preference, network and physical environment, the providers can provide the optimal network access and personalized recommendation. As shown in Fig.
he mobile communication develops from the first generation of mobile
communication systems (1G) to the fourth generation mobile communication system (4G), while the development of each generation has the operational capacity and representative technology, such as analog cellular technology of 1G; time division multiple access (TDMA), frequency division multiple access (FDMA), and other digital cellular technology supporting voice communication for 2G; code division multiple access (CDMA) supporting data and multimedia services for 3G; orthogonal frequency division multiplexing (OFDM) and multiple-input multiple-output (MIMO) supporting broadband data and mobile networks for 4G. In recent years, the rapid development of integrated circuit technology, communication system, and terminal capabilities deeply integrates the communication and computer techniques, various wireless access technologies are developed and wildly implemented. From the perspective of consumers, the initial 1G and 2G wireless networks networks provide the users with more mobile services and higher broadband experience. In the future, 5G wireless networks are expected to extensively improve the user experience, and establish a novel user-centric service model to make the users to freely enjoy mobile networking services [ .
Fig. 1.2 Service development from 1G to 5G (Source: Datang Wireless Mobile Innovation Center, December 2013)
However, the researches on 5G are still at its initial stage, although some documents have defined the technical specifications of 5G [
hows the advantage of 5G in
performance, compared to 4G and 4.5G. In addition, although some researchers have discussed how to construct the 5G network from multiple perspectives, such as air interface
, most of them focus on the technical details without a comprehensive
and systemic consideration. It can be predicted that 5G must include various techniques and involve
multiple features and cannot be defined by a representative service or technology. Considering the future development trend of computer, networking, and communication technologies, 5G will be a
virtualized, definable, green mobile communication system providing cloud-based wireless network infrastructure.
Fig. 1.3 The performance comparison between 4G, 4.5G, and 5G (Source: Datang Wireless Mobile Innovation Center, December 2013) References
1. A. Ghosh, N. Mangalvedhe, R. Ratasuk, B. Mondal, M. Cudak, E. Visotsky, T.A. Thomas, J.G. Andrews, P. Xia, H.S. Jo, et al., Heterogeneous cellular networks: from theory to practice. IEEE Commun. Mag. 50 (6), 54–64 (2012) ]
2. A. Gohil, H. Modi, S.K. Patel, 5G technology of mobile communication: a survey, in 2013 International Conference on Intelligent
Systems and Signal Processing (ISSP) (IEEE, Vallabh Vidhyanagar, Anand, 2013), pp. 288–292 ]3.
4. T. Janevski, 5G mobile phone concept, in 2009 6th IEEE Consumer Communications and Networking Conference (IEEE, Las Vegas, 2009), pp. 1–2 ]
5. S.G. Larew, T.A. Thomas, M. Cudak, A. Ghosh, Air interface design and ray tracing study for 5G millimeter wave communications,
in 2013 IEEE Globecom Workshops (GC Wkshps) (IEEE, Atlanta, 2013), pp. 117–122 ]6. Q.C. Li, H. Niu, A.T. Papathanassiou, G. Wu, 5G network capacity: key elements and technologies. IEEE Veh. Technol. Mag. 9 (1), 71–78 (2014) ]
7. G.R. MacCartney, J. Zhang, S. Nie, T.S. Rappaport, Path loss models for 5G millimeter wave propagation channels in urban microcells, in 2013 IEEE Global Communications Conference (GLOBECOM) (IEEE, Atlanta, 2013), pp. 3948–3953 ]
LTE advanced. IEEE Commun. Mag. 51 (2), 98–105 (2013) ]
9. M. Olsson, C. Cavdar, P. Frenger, S. Tombaz, D. Sabella, R. Jäntti, 5GrEEn: towards green 5G mobile networks, in The 9th IEEE
International Conference on Wireless and Mobile Computing, Networking and Communications (WiMob 2013),International Workshop on the Green Optimized Wireless Networks (GROWN 2013), IEEE Conference Proceedings, Lyon,
7th October, 2013, pp. 212–216
10. M.S. Pandey, M. Kumar, A. Panwar, I. Singh, A survey: wireless mobile technology generations with 5G. Int. J. Eng. 2 (4), 33–37
(2013)
11. T.S. Rappaport, S. Sun, R. Mayzus, H. Zhao, Y. Azar, K. Wang, G.N. Wong, J.K. Schulz, M. Samimi, F. Gutierrez, Millimeter wave
mobile communications for 5G cellular: it will work! IEEE Access 1, 335–349 (2013) ]12. A. Tudzarov, T. Janevski, Functional architecture for 5G mobile networks. Int. J. Adv. Sci. Technol. 32, 65–78 (2011)
13. L.-C. Wang, S. Rangapillai, A survey on green 5G cellular networks, in 2012 International Conference on Signal Processing and Communications (SPCOM) (IEEE, Bangalore, 2012), pp. 1–5 ]
Footnotes
© The Author(s) 2016
Yin Zhang and Min Chen, Cloud Based 5G Wireless Networks, SpringerBriefs in Computer Science, DOI 10.1007/978-3-319-47343-7_2
2. Cloud-Based Networking 1 2 Yin Zhang and Min Chen
(1) School of Information and Safety Engineering, Zhongnan University of Economics and Law, Wuhan, Hubei, China
(2) School of Computer Science and Technology, Huazhong University of Science and Technology, Wuhan City, China
Abstract
Cloud networking is an novel approach for building and managing secure private networks over the public Internet through the cloud computing infrastructure. In cloud networking, the traditional network functions and services including connectivity, security, management, and control are pushed to the cloud and published as services, such as Network Foundation Virtualization, Cloud Radio Access Networks, and Mobile Cloud Networking (MCN).
2.1 Network Foundation Virtualization
In simplest terms, Network Foundation Virtualization (NFV) is used to migrate the
telecommunication equipment from specialized platform to universal x86-based commercial off-the- shelf (COTS) servers. The current telecom networking devices are deployed by the private platforms, within which all the network elements are closed boxes, which cannot utilize the hardware resources mutually. Therefore, the capacity expansion of each devices relies on the additional hardware, while the hardware resources lie idle after the capacity reduction, which is quite time-consuming with poor elasticity and high cost. Through NFV, all the network elements are transformed into independent applications that can be flexibly deployed on a unified platform based on a standard server, storage, and exchange mechanism. As shown in Fig.
, with the decoupled software and hardware, the
capacity of every application is available to be expanded rapidly through increasing the virtual resources, and vice versa, which has enhanced the elasticity of the network dramatically.
Fig. 2.1 NFV vision (Source: ETSI)
The technological foundation of NFV is the cloud computing and virtualization techniques in Information Technology (IT) industry. Through the virtualization techniques, the universal resources of computing, storage, and networking provided by COSTS can decompose into a variety of virtual recourses for the use of upper applications. At the same time, the application and hardware are decoupled through the virtualization techniques, while the supply speed of resources has shortened from a few days to a few minutes. Through the cloud computing technology, the flexible expansion and reduction of the applications is accomplished for contributing to the matching of resources and business load, which does not only improve the resource utilization rate but also ensure the system response speed. Specifically, the deployment of NFV brings the following advantages:
The purchasing, operation and maintenance costs, and energy consumption of the operators are reduced. The business deployment is accelerated, while the innovation cycle is decreased. Specifically, the efficiency of testing and integration are improved, the development cost is reduced, and the conventional hardware deployment is replaced with the quick software installation. Network applications support multi-version and multi-tenant to enable the different applications, users, tenants sharing a unified platform, so the network sharing is possible. The personalized service of different physical domains and user groups are available, while the service modules can be rapidly expanded. The network is open, and the business innovation is able to cause new potential profit increasing point.
2.1.1 Development Status of NFV
Since founded in October 2012, the European Telecommunication Standards Institute Industry Specification Group for Network Functions Virtualization (ETSI ISG NFV) develops quickly, which has held six plenary sessions and includes the following works:
Technical Steering Committee (TSC): takes charge of the overall operating of ETSI ISG NFV; Architecture of the Virtualization Infrastructure (AVI): takes charge of the architecture of the virtualization infrastructure; Management and Orchestration (MANO): takes charge of management and orchestration; Software Architecture (SA): takes charge of software architecture; Reliability and Availability (R&A): takes charge of reliability and availability; Performance and Portability (P&P): takes charge of performance and portability; Security: takes charge of security.
Especially, four overall standards, i.e., Use Cases, Architecture Framework, Terminology for Main Concepts in NFV, and Virtualization Requirements, are finalized by TSC, including five working group (WG) under TSC: Evolution and Ecosystem (EVE), Interfaces and Architecture (IFA), Testing, Experimentation, and Open Source (TST), Security (SEC), and Reliability (REL).
Compared with the current network architecture including independent business network and operation support system (OSS), NFV is deconstructed vertically and horizontally. According to NFV architecture illustrated in Fig
, from the vertical the network consists of the following three layers:
NFV infrastructure (NFVI), Virtual Network Functions (VNFs), and Operation&Business Support Systems (OSS&BSS).
NFVI is a resource pool, from the perspective of cloud computing. The mappings of NFVI on
physical infrastructures are some geographically distributed data centers connected by the high- speed communication network.
VNFs correspond with various telecommunication service networks. Each physical network
element maps with a VNF. The needed resources fall into virtual computing/storage/exchange resources hosted by NFVI. Interfaces adopted by NFVI are still signaling interfaces defined by the traditional network. Moreover, it still adopts Network Element, Element Management System, and Network Management System (NE-EMS-NMS) framework as its service network management system.
OSS&BSS is the operation support layer needing to make necessary revising and adjusting for its virtualization.
Fig. 2.2 NFV architecture
By the horizontal view, NFV includes services network and management and orchestration: Services network is the telecommunication service networks.
Management and orchestration is the most significant difference between NFV and traditional
network, referred to as MANO. MANO is responsible for the management and orchestration of the overall NFVI resources, business network and mapping and association of NFVI resources, and the implementation of OSS business resource process. According to the NFV technology principle, a business network can be decomposed into a set of
VNF and VNF Link (VNFL), represented as VNF Forwarding Graph (VNF-FG). Each VNF consists of several VNF Components (VNFC) and an internal connection diagram, and each VNFC is mapped to a Virtual Machine (VM). Each VNFL corresponds to an Internet Protocol (IP) connection, which needs link resources, such as flow, Quality of Service (QoS), routing, and other parameters. Thus, the services network can make top-down dissolutions to get distributable resources through MANO. The corresponding VM resources and other resources are allocated by NFVI. In addition, the corresponding VNFL resources need to interact with the bearer network management system, and to be allocated by IP bearer network. For example, Fig
illustrates the services network deploying NFV.
Fig. 2.3 Services network deploying NFV
According to the current technical architecture of NFV, many manufacturers have already completed the proof of concept (POC) testing and verification, such as virtual IP Multimedia Subsystem (vIMS)
], virtual Customer Premise
Equipment (vCPE) [
. And they have been
demonstrated at the annual meeting of the World Radio Communication Conference (WRC) in 2014 to prove that NFV technology is available.
2.1.2 Technical Issues of NFV
Although the criterion defined by NFC is technically feasible, there is still a long way to realize its commercial application with the following issues
: Maturity: Due to its too large target, only four specifications have been completed after the first
phase, while many relevant specifications defined by other groups estimate to complete. Many problems have been postponed to the second phase, so there is still a long way to go to meet its mature standard.
Compatibility: Architecture defined by NFV is quite huge with many new interfaces, dividing
the closed telecom equipment manufacturers into several levels: hardware equipment suppliers, virtualization management software suppliers, virtualization software vendors, NFV Orchestrator (NFVO) software vendors, NFV system integrator, etc. Thus, the telecom network is transferred from a integration of hardware and software managed by one manufacture into a series integrations of hardware and software managed by several manufactures, so the complexity increases greatly. However, NFV only defines the architecture levels, while the detailed definition and implementation of the corresponding interfaces are to be coordinated by other technical organizations. Therefore, compared with the existing standard, the technical various manufactures in the future.
Flexibility: The lagging Self-Organization Network (SON) technology affects the expansion and
deduction of service level. According to the NFV architecture, although the needed resources of a new VNF are automatically deployed by MANO, its business network operational architecture still relies on the traditional EMS/NMS mechanism, and the connection between VNF and traffic routing is still deployed manually and the VNF plug and play is not available.
Reliability: Traditional telecom applications often require the reliability of 99.999 %, which
should not be decreased after its virtualization. Due to the special design, the reliability requirements of traditional telecom hardware are relatively high. However, the reliability of COTS equipment adopted by the virtualization is relatively lower, demanding compensation by raising the software reliability.
Integration: The current telecommunications equipment often uses special chips to realize user
plane. Considering the packet mangling, x86 has lower cost performance. Therefore, its virtualization will lead to the reduction of equipment integration. Currently there are several ways to solve this problem: (1) the Software Defined Network (SDN) is implemented to separate the control and operation of user plane equipment and offload the forwarded packet to the SDN switch; (2) the Intelligent Ethernet Card including packet processing module is implemented to offload packet processing burden.
Virtualization: Compared with computing and storage virtualization, network virtualization
technology is relatively backward. Although the current network virtualization technology has various types, it is a critical issue to integrate them into the NFVI. Telecommunication network is usually a distributed network needing sufficient network resources, which are decomposed to local network resource within data center, the bearer network resources among the data center, the bearer network resources between the service network and access network, etc. The allocation of the bearer network resources may involve the transport network resources allocation, which needs virtualization and automation. Currently the allocation still needs to fulfil through bearer network and transport network management, which is a long way to reach the automation.
Systematicity: NFV is expected to solve the problem of automatic deployment of business
network, which is a giant Information and Communication Technology (ICT) integration project from the perspective of architecture. NFV can be decomposed into NFVI integration, VNF integration, and business network integration, involving a number of systems, manufactures, areas, and interfaces, which makes the engineering more difficult than the current public/private cloud. Despite its automatic deployment, every link of the telecom network deployment (planning, implementation, testing, upgrade, optimization, operations, etc.) is involved and implemented. Therefore, it is a complicated issue to implement the deployment in the future, because the technical requirement for the integrator is very high. After the implementation of NFV architecture, automatic management and agility of the telecom network should ascend dramatically. The deployment cycle of a telecommunications device is decreased from a few months to a few hours, the expansion cycle is decreased from a few weeks to a few minutes, and the new business deployment cycle of the telecommunications network is decreased
2.2 Cloud Radio Access Networks
Cloud Radio Access Networks (Cloud-RAN) is a new type of wireless access network architecture based on the trend of current network conditions and technological progress. As a type of clean system, C-RAN is based on the Centralized Processing, Collaborative Radio, and Real-time Cloud Infrastructure. Its essence is to cut down the number of base station and reduce the energy consumption, adopt the collaboration and virtualization technology to realize the resources sharing and dynamic scheduling, improve the spectrum efficiency, and achieve low cost, high bandwidth, and flexible operation. C-RAN’s overall goal is to address the various challenges brought by the rapid development of mobile networks, such as energy consumption, construction and operation and maintenance costs, and spectrum resources., pursuing a sustainable business and profit growth in the future [ ].
As shown in Fig.
-RAN architecture mainly consists of the following three components: Distributed network consisting of a Remote Radio Unit (RRU) and an antenna.
Optical transmission network with high bandwidth and low latency which connects the RRU and the Bandwidth-Based Unit (BBU). Centralized base band processing pool consisting of high performance general processor and real-time virtual technology.
Fig. 2.4 C-RAN architecture
C-RAN architecture includes the following advantages: The centralized approach can greatly reduce the number of base stations and the energy consumption of the air conditioning systems. emission power without affecting the overall network coverage. Low transmission power means that the terminal’s battery life will be longer and the power consumption of wireless access networks will be reduced.
Different from the traditional distributed base station, C-RAN breaks the fixed connection relationship between RRU and BBU that each RRU does not belong to any BBU. Sending and receiving signals in RRU is in a virtual BBU, while the processing capacity of the virtual base station is supported by the assigned processors in the real-time virtual allocation base band pool.
In the C-RAN architecture, the sites of BBU can be reduced by one to two orders of magnitude. Centralized base band pool and related auxiliary equipment can be placed in some key central machine room for simple operation and management. Though the number of RRU is not reduced in C- RAN, due to the small size and low power consumption of these devices, they can be easily deployed in a limited space with the power supply system and without the frequent maintenance. As a result, it can accelerate the speed of the operational network construction.
2.3 Mobile Cloud Networking
2 Mobile cloud networking (MCN) is a large-scale integrated project funded by the European
Commission EP7, focusing on the implementation of cloud computing and network function virtualization to achieve the virtual cellular network. It is designed as a completely cloud-based mobile communication and application platform. More specifically, it aims to investigate, implement, and evaluate the LTE mobile communication system’s technology base. This mobile communication system provides atomic level of service based on the mobile network and decentralized computing and intelligent storage, in order to support atomical services and flexible payment.
As shown in Fig.
CN is expected to achieve the following goals:
MCN is expected to provide the basic network infrastructure and platform software as a service for solving the resources waste problems (energy, bandwidth, etc.) facing the inflexible traditional network, and supporting payment on demand, self-service, flexible consumption, remote access, and other services.
The structure of cloud computing is unable to support the integration with the mobile ecosystem. Therefore, MCN attempts to extend the cloud computing concept from data center to the mobile terminal users. Specifically, the new virtualization layer and monitoring system is designed, the new mobile platform is developed for the future mobile services and application supporting cloud, and the end-to-end MCN services are provided.
Fig. 2.5 The goals of MCN
MCN focuses on two main principles: (1) the cloud computing service must illustrate the resource pool, (2) the architecture is service-oriented. The related work of MCN mainly consists of the following components: cloud computing infrastructure, wireless cloud, mobile core network cloud, and mobile platform services.
MCN architecture is service-oriented, in which the functional elements are modularized into service. The services provided by MCN are derived from the resources that can be both physical and virtualized. The MCN service is divided into two kinds: atomic-level service and composite service.
Figure
illustrates the following crucial entities and relationships in MCN architecture: Service Manager (SM): provides an user-oriented visual external interface and supports multi- tenant services.
Service Orchestrator (SO): provides the actual services. Cloud Controller (CC): supports for the deployment and configures SOs.
References
1. G. Carella, M. Corici, P. Crosta, P. Comi, T.M. Bohnert, A.A. Corici, D. Vingarzan, T. Magedanz, Cloudified IP multimedia subsystem (IMS) for network function virtualization (NFV)-based architectures, in 2014 IEEE Symposium on Computers and Communications (ISCC) (IEEE, Madeira, 2014), pp. 1–6